I used RaspyFi for months without much problem, the main one being network drop-outs (i.e. I couldn't access my RP through the WebUI).

I tried using my RP yesterday, but I just couldn't. I unplugged everything I re-installed like it was the first time, including re-writing on the SD card. That did the trick.

Then, I had the same problem this morning, but the "hard reboot" didn't work. After I plug the RP, the red LED stays on and the green "ACT" led flashed once. All the other LEDs are working. I tested my Ethernet cable on my computer and it worked.

I know the RP is not communicating with my USB stick because it has a light that opens up when it is connected, which it's not doing right now.

I have tried Blueberry's fix (using his .elf files) and it didn't work